The Center for Reproductive Biology Research has been serving the scientific community for approximately 25 years as a P30 Center. Since the center for Population Research of NICHD has changed their application format so that P-30 Center Grants will be eliminated, we have been advised to move to the U54 Center Grant mechanism. The theme chosen and approved for the renewal application is "Mechanisms Involved in Female Reproduction". The purpose of this Center will be to establish a comprehensive research and training program to investigate the molecular mechanisms governing female reproduction. This research will be accomplished by four research projects. Project I is titled "Steroid receptor activation pathways in female reproductive behavior", and will investigate the interactions of steroid hormone receptors and neurotransmitters in the regulation of female hypothalamic function. Project II, titled "Transgenic mouse models to study ovarian function," will investigate the role of Novel. 1, a member of the TGFb gene family, and Germ Cell Nuclear Factor, a member of the steroid hormone receptor superfamily, in oogenesis and folliculogenesis. Project III, titled "Cellular signals in ovulation and luteinization", will investigate the regulation and interactions of members of the steroid hormone receptor superfamily in folliculogenesis and luteinization. Finally, Project IV titled "Molecular approaches for the evaluation of human fertility", will identify the molecular interactions of human zona pellucida proteins with human sperm in the evaluation of human infertility. These research projects will be supported by four Cores. The Cores chosen are the Administrative Core (Core A), the Animal Core (Core B), the Cell Culture Core (Core C) and an Integrated Microscopy Core (Core D). The Administrative Core will provide the Center with centralized management. The Animal Core will serve as a resource for the maintenance and identification of transgenic and knockout mice, as well as, a centralization of the technology required to generate these animals and perform technical surgical manipulations on these animals. The Cell Culture Core will provide investigators with specific reagents for the culture of primary cells and cell lines, as well as, the expertise required to manipulate these cells. The Integrated Microscopy Core will aid investigators in the histological immunohistochemical and ultrastructural analysis required in the execution of their projects. The research in this Center for Reproductive Biology Research application will investigate the molecular regulation of female reproduction and fertility and foster the training of investigators in the field of reproductive biology.